Biomolecular Preservation of Miocene Fossil Liquidambar from Tiantai,China and Clarkia,USA:Implications for Palaeoenvironmental Study

作     者：XIAO Liang YANG Hong HE Yuli HE Wenlong LI Xiangchuan GUO Junfeng HUI Kaixuan 

作者机构：College of Earth Science and Resourcesand Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of EducationChang’an University Laboratory of Terrestrial EnvironmentsDepartment of Science and TechnologyCollege of Arts and SciencesBryant University School of Earth Sciences and Key Laboratory of Mineral Resources in Western China (Gansu Province)Lanzhou University College of Geology and EnvironmentXi’an University of Science and Technology 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2015年第89卷第4期

页      面：1076-1087页

核心收录：

学科分类：070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学] 

基　　金：supported by National Natural Science Foundation of China (No.41202009,41172022,41202008) State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology,CAS) (No.123112) Special Fund for Basic Scientific Research of Central College,Chang’an University (No.2013G3274021,2013G1271101,2014G3272013,2014G1271061) 

主　　题：Liquidambar Py-GC-MS Miocene Biomolecules palaeoenvironment 

摘      要：Biomolecular characteristics of fossil Liquidambar from the Miocene Shengxian Formation, Tiantai, Zhejiang province in eastern China and Miocene Clarkia sediment, Idaho, U.S.A., are obtained by means of Pyrolysis-Gas chromatography-Mass spectrometry analysis （Py-GC-MS）. Their modern equivalent （Liquidambarformosana） collected from Nanjing, eastern China, is also analyzed for comparison. The total ion chromatograms （TIC） of modern L. formosana leaves shows abundant pyrolysates of iignin, polysaccharide, aliphatic acid, and amino acid. However, only one polysaccharide molecule, i.e., levoglucosan, is retained in fossil Liquidambar leaves from the two Miocene sites with the Tiantai specimen possessing higher intensity. As expected, some lignin pyrolysates including benzene, phenol, guaiacol, vinylphenol and their derivatives, are detected in Miocene Tiantai L. miosinica. However, the lignin components with large molecular weight other than benzene and phenol compounds, are absent in Miocene Clarkia L. pachyphyllum. Abundant pristene and homologous series of n-alk-l-ene/n-alkane pairs with a long retention time are shown in pyrograms of both Tiantai and Clarkia fossils. Based upon our Py-GC-MS data, the molecular preservation in these Liquidambar leaf samples can be ranked as the following （from high to low quality respectively）： modern sample 〉Tiantai sample 〉Clarkia sample. Vinyl phenol, an important compound, is present in modern and Tiantai Liquidambar leaves, while absent in Clarkia sample, implying that vinyl phenol may be sourced from lignin for Liquidambar leaves. Our data support the hypothesis of in situ polymerization for the origin of long-chain homologous series of n-alk-l-ene/n- alkane pairs as leaf alteration products. Our data have implications of the impact of leaf degradation toward biases for palaeoenvironmental reconstruction using stable carbon isotope of fossil plants, and suggest the importance of evaluating molecular preservation of fossil leaf t